He was the third but eldest surviving son of John George I, Elector of Saxony[1] and Magdalene Sibylle of Prussia, his second spouse.

[1] In 1657 John George made an arrangement with his three brothers with the object of preventing disputes over their separate territories, and in 1664 he entered into friendly relations with Louis XIV.

He received money from the French king, but the existence of a strong anti-French party in Saxony induced him occasionally to respond to the overtures of the Emperor Leopold I.

[4] His enormous expenditure on the arts compelled John George in 1661 to grant greater control over monetary matters to the estates, a step which laid the foundation of the later system of finance in Saxony.

Locally mined silver filled the electorate's empty treasury, and the Leipzig Trade Fair and the Bohemian Exulanten of 1654 also stimulated economic activity.